X-Ray Induced Currents in Polyvinylidene Fluoride

Abstract

The radiation-induced current J _RIC during X-ray irradiation and the delayed radiation induced current J _DRIC after cessation of irradiation were investigated in β-form polyvinylidene fluoride (PVDF). J _RIC showed complicated transients and both J _RIC and the dark current J _d decreased with field in the high-field region. The TSC spectra in β-PVDF thermoelectrets and the discharging currents revealed the accumulation of hetero-space charge, which is closely related to the decrease of J _d with the field. Thus the anomalous transients and field-dependences of J _RIC could be qualitatively explained through the space charge. The temperature and X-ray-intensity dependences of J _RIC and the temperature dependence of the time constants for the decay of J _DRIC are also discussed on the basis of a simplified band model with a single set of electron traps.